[2017] | 1 | /* -*- C++ -*- |
---|
| 2 | * |
---|
| 3 | * This file is a part of LEMON, a generic C++ optimization library |
---|
| 4 | * |
---|
| 5 | * Copyright (C) 2003-2006 |
---|
| 6 | * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport |
---|
| 7 | * (Egervary Research Group on Combinatorial Optimization, EGRES). |
---|
| 8 | * |
---|
| 9 | * Permission to use, modify and distribute this software is granted |
---|
| 10 | * provided that this copyright notice appears in all copies. For |
---|
| 11 | * precise terms see the accompanying LICENSE file. |
---|
| 12 | * |
---|
| 13 | * This software is provided "AS IS" with no warranty of any kind, |
---|
| 14 | * express or implied, and with no claim as to its suitability for any |
---|
| 15 | * purpose. |
---|
| 16 | * |
---|
| 17 | */ |
---|
| 18 | |
---|
| 19 | #ifndef LEMON_MIN_COST_ARBORESCENCE_H |
---|
| 20 | #define LEMON_MIN_COST_ARBORESCENCE_H |
---|
| 21 | |
---|
| 22 | ///\ingroup spantree |
---|
| 23 | ///\file |
---|
| 24 | ///\brief Minimum Cost Arborescence algorithm. |
---|
| 25 | |
---|
| 26 | #include <vector> |
---|
| 27 | |
---|
| 28 | #include <lemon/list_graph.h> |
---|
| 29 | |
---|
| 30 | namespace lemon { |
---|
| 31 | |
---|
| 32 | |
---|
| 33 | /// \brief Default traits class of MinCostArborescence class. |
---|
| 34 | /// |
---|
| 35 | /// Default traits class of MinCostArborescence class. |
---|
| 36 | /// \param _Graph Graph type. |
---|
| 37 | /// \param _CostMap Type of cost map. |
---|
| 38 | template <class _Graph, class _CostMap> |
---|
| 39 | struct MinCostArborescenceDefaultTraits{ |
---|
| 40 | |
---|
| 41 | /// \brief The graph type the algorithm runs on. |
---|
| 42 | typedef _Graph Graph; |
---|
| 43 | |
---|
| 44 | /// \brief The type of the map that stores the edge costs. |
---|
| 45 | /// |
---|
| 46 | /// The type of the map that stores the edge costs. |
---|
| 47 | /// It must meet the \ref concept::ReadMap "ReadMap" concept. |
---|
| 48 | typedef _CostMap CostMap; |
---|
| 49 | |
---|
| 50 | /// \brief The value type of the costs. |
---|
| 51 | /// |
---|
| 52 | /// The value type of the costs. |
---|
| 53 | typedef typename CostMap::Value Value; |
---|
| 54 | |
---|
| 55 | /// \brief The type of the map that stores which edges are |
---|
| 56 | /// in the arborescence. |
---|
| 57 | /// |
---|
| 58 | /// The type of the map that stores which edges are in the arborescence. |
---|
| 59 | /// It must meet the \ref concept::ReadWriteMap "ReadWriteMap" concept. |
---|
| 60 | /// Initially it will be setted to false on each edge. The algorithm |
---|
| 61 | /// may set each value one time to true and maybe after it to false again. |
---|
| 62 | /// Therefore you cannot use maps like BackInserteBoolMap with this |
---|
| 63 | /// algorithm. |
---|
| 64 | typedef typename Graph::template EdgeMap<bool> ArborescenceMap; |
---|
| 65 | |
---|
| 66 | /// \brief Instantiates a ArborescenceMap. |
---|
| 67 | /// |
---|
| 68 | /// This function instantiates a \ref ArborescenceMap. |
---|
| 69 | /// \param _graph is the graph, to which we would like to define the |
---|
| 70 | /// ArborescenceMap. |
---|
| 71 | static ArborescenceMap *createArborescenceMap(const Graph &_graph){ |
---|
| 72 | return new ArborescenceMap(_graph); |
---|
| 73 | } |
---|
| 74 | |
---|
| 75 | }; |
---|
| 76 | |
---|
| 77 | /// \ingroup spantree |
---|
| 78 | /// |
---|
| 79 | /// \brief %MinCostArborescence algorithm class. |
---|
| 80 | /// |
---|
| 81 | /// This class provides an efficient implementation of |
---|
| 82 | /// %MinCostArborescence algorithm. The arborescence is a tree |
---|
| 83 | /// which is directed from a given source node of the graph. One or |
---|
| 84 | /// more sources should be given for the algorithm and it will calculate |
---|
| 85 | /// the minimum cost subgraph which are union of arborescences with the |
---|
| 86 | /// given sources and spans all the nodes which are reachable from the |
---|
| 87 | /// sources. The time complexity of the algorithm is O(n^2 + e). |
---|
| 88 | /// |
---|
| 89 | /// \param _Graph The graph type the algorithm runs on. The default value |
---|
| 90 | /// is \ref ListGraph. The value of _Graph is not used directly by |
---|
| 91 | /// MinCostArborescence, it is only passed to |
---|
| 92 | /// \ref MinCostArborescenceDefaultTraits. |
---|
| 93 | /// \param _CostMap This read-only EdgeMap determines the costs of the |
---|
| 94 | /// edges. It is read once for each edge, so the map may involve in |
---|
| 95 | /// relatively time consuming process to compute the edge cost if |
---|
| 96 | /// it is necessary. The default map type is \ref |
---|
| 97 | /// concept::StaticGraph::EdgeMap "Graph::EdgeMap<int>". The value |
---|
| 98 | /// of _CostMap is not used directly by MinCostArborescence, |
---|
| 99 | /// it is only passed to \ref MinCostArborescenceDefaultTraits. |
---|
| 100 | /// \param _Traits Traits class to set various data types used |
---|
| 101 | /// by the algorithm. The default traits class is |
---|
| 102 | /// \ref MinCostArborescenceDefaultTraits |
---|
| 103 | /// "MinCostArborescenceDefaultTraits<_Graph,_CostMap>". See \ref |
---|
| 104 | /// MinCostArborescenceDefaultTraits for the documentation of a |
---|
| 105 | /// MinCostArborescence traits class. |
---|
| 106 | /// |
---|
| 107 | /// \author Balazs Dezso |
---|
| 108 | #ifndef DOXYGEN |
---|
| 109 | template <typename _Graph = ListGraph, |
---|
| 110 | typename _CostMap = typename _Graph::template EdgeMap<int>, |
---|
| 111 | typename _Traits = |
---|
| 112 | MinCostArborescenceDefaultTraits<_Graph, _CostMap> > |
---|
| 113 | #else |
---|
| 114 | template <typename _Graph, typename _CostMap, typedef _Traits> |
---|
| 115 | #endif |
---|
| 116 | class MinCostArborescence { |
---|
| 117 | public: |
---|
| 118 | |
---|
| 119 | /// \brief \ref Exception for uninitialized parameters. |
---|
| 120 | /// |
---|
| 121 | /// This error represents problems in the initialization |
---|
| 122 | /// of the parameters of the algorithms. |
---|
| 123 | class UninitializedParameter : public lemon::UninitializedParameter { |
---|
| 124 | public: |
---|
| 125 | virtual const char* exceptionName() const { |
---|
| 126 | return "lemon::MinCostArborescence::UninitializedParameter"; |
---|
| 127 | } |
---|
| 128 | }; |
---|
| 129 | |
---|
| 130 | /// The traits. |
---|
| 131 | typedef _Traits Traits; |
---|
| 132 | /// The type of the underlying graph. |
---|
| 133 | typedef typename Traits::Graph Graph; |
---|
| 134 | /// The type of the map that stores the edge costs. |
---|
| 135 | typedef typename Traits::CostMap CostMap; |
---|
| 136 | ///The type of the costs of the edges. |
---|
| 137 | typedef typename Traits::Value Value; |
---|
| 138 | ///The type of the map that stores which edges are in the arborescence. |
---|
| 139 | typedef typename Traits::ArborescenceMap ArborescenceMap; |
---|
| 140 | |
---|
| 141 | protected: |
---|
| 142 | |
---|
| 143 | typedef typename Graph::Node Node; |
---|
| 144 | typedef typename Graph::Edge Edge; |
---|
| 145 | typedef typename Graph::NodeIt NodeIt; |
---|
| 146 | typedef typename Graph::EdgeIt EdgeIt; |
---|
| 147 | typedef typename Graph::InEdgeIt InEdgeIt; |
---|
| 148 | typedef typename Graph::OutEdgeIt OutEdgeIt; |
---|
| 149 | |
---|
| 150 | struct CostEdge { |
---|
| 151 | |
---|
| 152 | Edge edge; |
---|
| 153 | Value value; |
---|
| 154 | |
---|
| 155 | CostEdge() {} |
---|
| 156 | CostEdge(Edge _edge, Value _value) : edge(_edge), value(_value) {} |
---|
| 157 | |
---|
| 158 | }; |
---|
| 159 | |
---|
| 160 | const Graph* graph; |
---|
| 161 | const CostMap* cost; |
---|
| 162 | |
---|
| 163 | ArborescenceMap* _arborescence_map; |
---|
| 164 | bool local_arborescence_map; |
---|
| 165 | |
---|
| 166 | typedef typename Graph::template NodeMap<int> LevelMap; |
---|
| 167 | LevelMap *_level; |
---|
| 168 | |
---|
| 169 | typedef typename Graph::template NodeMap<CostEdge> CostEdgeMap; |
---|
| 170 | CostEdgeMap *_cost_edges; |
---|
| 171 | |
---|
| 172 | struct StackLevel { |
---|
| 173 | |
---|
| 174 | std::vector<CostEdge> edges; |
---|
| 175 | int node_level; |
---|
| 176 | |
---|
| 177 | }; |
---|
| 178 | |
---|
| 179 | std::vector<StackLevel> level_stack; |
---|
| 180 | std::vector<Node> queue; |
---|
| 181 | |
---|
| 182 | int node_counter; |
---|
| 183 | |
---|
| 184 | public: |
---|
| 185 | |
---|
| 186 | /// \name Named template parameters |
---|
| 187 | |
---|
| 188 | /// @{ |
---|
| 189 | |
---|
| 190 | template <class T> |
---|
| 191 | struct DefArborescenceMapTraits : public Traits { |
---|
| 192 | typedef T ArborescenceMap; |
---|
| 193 | static ArborescenceMap *createArborescenceMap(const Graph &) |
---|
| 194 | { |
---|
| 195 | throw UninitializedParameter(); |
---|
| 196 | } |
---|
| 197 | }; |
---|
| 198 | |
---|
| 199 | /// \brief \ref named-templ-param "Named parameter" for |
---|
| 200 | /// setting ArborescenceMap type |
---|
| 201 | /// |
---|
| 202 | /// \ref named-templ-param "Named parameter" for setting |
---|
| 203 | /// ArborescenceMap type |
---|
| 204 | template <class T> |
---|
| 205 | struct DefArborescenceMap |
---|
| 206 | : public MinCostArborescence<Graph, CostMap, |
---|
| 207 | DefArborescenceMapTraits<T> > { |
---|
| 208 | typedef MinCostArborescence<Graph, CostMap, |
---|
| 209 | DefArborescenceMapTraits<T> > Create; |
---|
| 210 | }; |
---|
| 211 | |
---|
| 212 | /// @} |
---|
| 213 | |
---|
| 214 | /// \brief Constructor. |
---|
| 215 | /// |
---|
| 216 | /// \param _graph The graph the algorithm will run on. |
---|
| 217 | /// \param _cost The cost map used by the algorithm. |
---|
| 218 | MinCostArborescence(const Graph& _graph, const CostMap& _cost) |
---|
| 219 | : graph(&_graph), cost(&_cost), |
---|
| 220 | _arborescence_map(0), local_arborescence_map(false), |
---|
| 221 | _level(0), _cost_edges(0) {} |
---|
| 222 | |
---|
| 223 | /// \brief Destructor. |
---|
| 224 | ~MinCostArborescence() { |
---|
| 225 | destroyStructures(); |
---|
| 226 | } |
---|
| 227 | |
---|
| 228 | /// \brief Sets the arborescence map. |
---|
| 229 | /// |
---|
| 230 | /// Sets the arborescence map. |
---|
| 231 | /// \return \c (*this) |
---|
| 232 | MinCostArborescence& arborescenceMap(ArborescenceMap& m) { |
---|
| 233 | _arborescence_map = &m; |
---|
| 234 | return *this; |
---|
| 235 | } |
---|
| 236 | |
---|
| 237 | /// \name Query Functions |
---|
| 238 | /// The result of the %MinCostArborescence algorithm can be obtained |
---|
| 239 | /// using these functions.\n |
---|
| 240 | /// Before the use of these functions, |
---|
| 241 | /// either run() or start() must be called. |
---|
| 242 | |
---|
| 243 | /// @{ |
---|
| 244 | |
---|
| 245 | /// \brief Returns a reference to the arborescence map. |
---|
| 246 | /// |
---|
| 247 | /// Returns a reference to the arborescence map. |
---|
| 248 | const ArborescenceMap& arborescenceMap() const { |
---|
| 249 | return *_arborescence_map; |
---|
| 250 | } |
---|
| 251 | |
---|
| 252 | /// \brief Returns true if the edge is in the arborescence. |
---|
| 253 | /// |
---|
| 254 | /// Returns true if the edge is in the arborescence. |
---|
| 255 | /// \param edge The edge of the graph. |
---|
| 256 | /// \pre \ref run() must be called before using this function. |
---|
| 257 | bool arborescenceEdge(Edge edge) const { |
---|
| 258 | return (*_arborescence_map)[edge]; |
---|
| 259 | } |
---|
| 260 | |
---|
| 261 | /// \brief Returns the cost of the arborescence. |
---|
| 262 | /// |
---|
| 263 | /// Returns the cost of the arborescence. |
---|
| 264 | Value arborescenceCost() const { |
---|
| 265 | Value sum = 0; |
---|
| 266 | for (EdgeIt it(*graph); it != INVALID; ++it) { |
---|
| 267 | if (arborescenceEdge(it)) { |
---|
| 268 | sum += (*cost)[it]; |
---|
| 269 | } |
---|
| 270 | } |
---|
| 271 | return sum; |
---|
| 272 | } |
---|
| 273 | |
---|
| 274 | /// @} |
---|
| 275 | |
---|
| 276 | /// \name Execution control |
---|
| 277 | /// The simplest way to execute the algorithm is to use |
---|
| 278 | /// one of the member functions called \c run(...). \n |
---|
| 279 | /// If you need more control on the execution, |
---|
| 280 | /// first you must call \ref init(), then you can add several |
---|
| 281 | /// source nodes with \ref addSource(). |
---|
| 282 | /// Finally \ref start() will perform the actual path |
---|
| 283 | /// computation. |
---|
| 284 | |
---|
| 285 | ///@{ |
---|
| 286 | |
---|
| 287 | /// \brief Initializes the internal data structures. |
---|
| 288 | /// |
---|
| 289 | /// Initializes the internal data structures. |
---|
| 290 | /// |
---|
| 291 | void init() { |
---|
| 292 | initStructures(); |
---|
| 293 | for (NodeIt it(*graph); it != INVALID; ++it) { |
---|
| 294 | (*_cost_edges)[it].edge = INVALID; |
---|
| 295 | (*_level)[it] = -3; |
---|
| 296 | } |
---|
| 297 | for (EdgeIt it(*graph); it != INVALID; ++it) { |
---|
| 298 | _arborescence_map->set(it, false); |
---|
| 299 | } |
---|
| 300 | } |
---|
| 301 | |
---|
| 302 | /// \brief Adds a new source node. |
---|
| 303 | /// |
---|
| 304 | /// Adds a new source node to the algorithm. |
---|
| 305 | void addSource(Node source) { |
---|
| 306 | std::vector<Node> nodes; |
---|
| 307 | nodes.push_back(source); |
---|
| 308 | while (!nodes.empty()) { |
---|
| 309 | Node node = nodes.back(); |
---|
| 310 | nodes.pop_back(); |
---|
| 311 | for (OutEdgeIt it(*graph, node); it != INVALID; ++it) { |
---|
| 312 | if ((*_level)[graph->target(it)] == -3) { |
---|
| 313 | (*_level)[graph->target(it)] = -2; |
---|
| 314 | nodes.push_back(graph->target(it)); |
---|
| 315 | queue.push_back(graph->target(it)); |
---|
| 316 | } |
---|
| 317 | } |
---|
| 318 | } |
---|
| 319 | (*_level)[source] = -1; |
---|
| 320 | } |
---|
| 321 | |
---|
| 322 | /// \brief Processes the next node in the priority queue. |
---|
| 323 | /// |
---|
| 324 | /// Processes the next node in the priority queue. |
---|
| 325 | /// |
---|
| 326 | /// \return The processed node. |
---|
| 327 | /// |
---|
| 328 | /// \warning The queue must not be empty! |
---|
| 329 | Node processNextNode() { |
---|
| 330 | node_counter = 0; |
---|
| 331 | Node node = queue.back(); |
---|
| 332 | queue.pop_back(); |
---|
| 333 | if ((*_level)[node] == -2) { |
---|
| 334 | Edge edge = prepare(node); |
---|
| 335 | while ((*_level)[graph->source(edge)] != -1) { |
---|
| 336 | if ((*_level)[graph->source(edge)] >= 0) { |
---|
| 337 | edge = contract(bottom((*_level)[graph->source(edge)])); |
---|
| 338 | } else { |
---|
| 339 | edge = prepare(graph->source(edge)); |
---|
| 340 | } |
---|
| 341 | } |
---|
| 342 | finalize(graph->target(edge)); |
---|
| 343 | level_stack.clear(); |
---|
| 344 | } |
---|
| 345 | return node; |
---|
| 346 | } |
---|
| 347 | |
---|
| 348 | /// \brief Returns the number of the nodes to be processed. |
---|
| 349 | /// |
---|
| 350 | /// Returns the number of the nodes to be processed. |
---|
| 351 | int queueSize() const { |
---|
| 352 | return queue.size(); |
---|
| 353 | } |
---|
| 354 | |
---|
| 355 | /// \brief Returns \c false if there are nodes to be processed. |
---|
| 356 | /// |
---|
| 357 | /// Returns \c false if there are nodes to be processed. |
---|
| 358 | bool emptyQueue() const { |
---|
| 359 | return queue.empty(); |
---|
| 360 | } |
---|
| 361 | |
---|
| 362 | /// \brief Executes the algorithm. |
---|
| 363 | /// |
---|
| 364 | /// Executes the algorithm. |
---|
| 365 | /// |
---|
| 366 | /// \pre init() must be called and at least one node should be added |
---|
| 367 | /// with addSource() before using this function. |
---|
| 368 | /// |
---|
| 369 | ///\note mca.start() is just a shortcut of the following code. |
---|
| 370 | ///\code |
---|
| 371 | ///while (!mca.emptyQueue()) { |
---|
| 372 | /// mca.processNextNode(); |
---|
| 373 | ///} |
---|
| 374 | ///\endcode |
---|
| 375 | void start() { |
---|
| 376 | while (!emptyQueue()) { |
---|
| 377 | processNextNode(); |
---|
| 378 | } |
---|
| 379 | } |
---|
| 380 | |
---|
| 381 | /// \brief Runs %MinCostArborescence algorithm from node \c s. |
---|
| 382 | /// |
---|
| 383 | /// This method runs the %MinCostArborescence algorithm from |
---|
| 384 | /// a root node \c s. |
---|
| 385 | /// |
---|
| 386 | ///\note mca.run(s) is just a shortcut of the following code. |
---|
| 387 | ///\code |
---|
| 388 | ///mca.init(); |
---|
| 389 | ///mca.addSource(s); |
---|
| 390 | ///mca.start(); |
---|
| 391 | ///\endcode |
---|
| 392 | void run(Node node) { |
---|
| 393 | init(); |
---|
| 394 | addSource(node); |
---|
| 395 | start(); |
---|
| 396 | } |
---|
| 397 | |
---|
| 398 | ///@} |
---|
| 399 | |
---|
| 400 | protected: |
---|
| 401 | |
---|
| 402 | void initStructures() { |
---|
| 403 | if (!_arborescence_map) { |
---|
| 404 | local_arborescence_map = true; |
---|
| 405 | _arborescence_map = Traits::createArborescenceMap(*graph); |
---|
| 406 | } |
---|
| 407 | if (!_level) { |
---|
| 408 | _level = new LevelMap(*graph); |
---|
| 409 | } |
---|
| 410 | if (!_cost_edges) { |
---|
| 411 | _cost_edges = new CostEdgeMap(*graph); |
---|
| 412 | } |
---|
| 413 | } |
---|
| 414 | |
---|
| 415 | void destroyStructures() { |
---|
| 416 | if (_level) { |
---|
| 417 | delete _level; |
---|
| 418 | } |
---|
| 419 | if (!_cost_edges) { |
---|
| 420 | delete _cost_edges; |
---|
| 421 | } |
---|
| 422 | if (local_arborescence_map) { |
---|
| 423 | delete _arborescence_map; |
---|
| 424 | } |
---|
| 425 | } |
---|
| 426 | |
---|
| 427 | Edge prepare(Node node) { |
---|
| 428 | std::vector<Node> nodes; |
---|
| 429 | (*_level)[node] = node_counter; |
---|
| 430 | for (InEdgeIt it(*graph, node); it != INVALID; ++it) { |
---|
| 431 | Edge edge = it; |
---|
| 432 | Value value = (*cost)[it]; |
---|
| 433 | if (graph->source(edge) == node || |
---|
| 434 | (*_level)[graph->source(edge)] == -3) continue; |
---|
| 435 | if ((*_cost_edges)[graph->source(edge)].edge == INVALID) { |
---|
| 436 | (*_cost_edges)[graph->source(edge)].edge = edge; |
---|
| 437 | (*_cost_edges)[graph->source(edge)].value = value; |
---|
| 438 | nodes.push_back(graph->source(edge)); |
---|
| 439 | } else { |
---|
| 440 | if ((*_cost_edges)[graph->source(edge)].value > value) { |
---|
| 441 | (*_cost_edges)[graph->source(edge)].edge = edge; |
---|
| 442 | (*_cost_edges)[graph->source(edge)].value = value; |
---|
| 443 | } |
---|
| 444 | } |
---|
| 445 | } |
---|
| 446 | CostEdge minimum = (*_cost_edges)[nodes[0]]; |
---|
| 447 | for (int i = 1; i < (int)nodes.size(); ++i) { |
---|
| 448 | if ((*_cost_edges)[nodes[i]].value < minimum.value) { |
---|
| 449 | minimum = (*_cost_edges)[nodes[i]]; |
---|
| 450 | } |
---|
| 451 | } |
---|
| 452 | StackLevel level; |
---|
| 453 | level.node_level = node_counter; |
---|
| 454 | for (int i = 0; i < (int)nodes.size(); ++i) { |
---|
| 455 | (*_cost_edges)[nodes[i]].value -= minimum.value; |
---|
| 456 | level.edges.push_back((*_cost_edges)[nodes[i]]); |
---|
| 457 | (*_cost_edges)[nodes[i]].edge = INVALID; |
---|
| 458 | } |
---|
| 459 | level_stack.push_back(level); |
---|
| 460 | ++node_counter; |
---|
| 461 | _arborescence_map->set(minimum.edge, true); |
---|
| 462 | return minimum.edge; |
---|
| 463 | } |
---|
| 464 | |
---|
| 465 | Edge contract(int node_bottom) { |
---|
| 466 | std::vector<Node> nodes; |
---|
| 467 | while (!level_stack.empty() && |
---|
| 468 | level_stack.back().node_level >= node_bottom) { |
---|
| 469 | for (int i = 0; i < (int)level_stack.back().edges.size(); ++i) { |
---|
| 470 | Edge edge = level_stack.back().edges[i].edge; |
---|
| 471 | Value value = level_stack.back().edges[i].value; |
---|
| 472 | if ((*_level)[graph->source(edge)] >= node_bottom) continue; |
---|
| 473 | if ((*_cost_edges)[graph->source(edge)].edge == INVALID) { |
---|
| 474 | (*_cost_edges)[graph->source(edge)].edge = edge; |
---|
| 475 | (*_cost_edges)[graph->source(edge)].value = value; |
---|
| 476 | nodes.push_back(graph->source(edge)); |
---|
| 477 | } else { |
---|
| 478 | if ((*_cost_edges)[graph->source(edge)].value > value) { |
---|
| 479 | (*_cost_edges)[graph->source(edge)].edge = edge; |
---|
| 480 | (*_cost_edges)[graph->source(edge)].value = value; |
---|
| 481 | } |
---|
| 482 | } |
---|
| 483 | } |
---|
| 484 | level_stack.pop_back(); |
---|
| 485 | } |
---|
| 486 | CostEdge minimum = (*_cost_edges)[nodes[0]]; |
---|
| 487 | for (int i = 1; i < (int)nodes.size(); ++i) { |
---|
| 488 | if ((*_cost_edges)[nodes[i]].value < minimum.value) { |
---|
| 489 | minimum = (*_cost_edges)[nodes[i]]; |
---|
| 490 | } |
---|
| 491 | } |
---|
| 492 | StackLevel level; |
---|
| 493 | level.node_level = node_bottom; |
---|
| 494 | for (int i = 0; i < (int)nodes.size(); ++i) { |
---|
| 495 | (*_cost_edges)[nodes[i]].value -= minimum.value; |
---|
| 496 | level.edges.push_back((*_cost_edges)[nodes[i]]); |
---|
| 497 | (*_cost_edges)[nodes[i]].edge = INVALID; |
---|
| 498 | } |
---|
| 499 | level_stack.push_back(level); |
---|
| 500 | _arborescence_map->set(minimum.edge, true); |
---|
| 501 | return minimum.edge; |
---|
| 502 | } |
---|
| 503 | |
---|
| 504 | int bottom(int level) { |
---|
| 505 | int k = level_stack.size() - 1; |
---|
| 506 | while (level_stack[k].node_level > level) { |
---|
| 507 | --k; |
---|
| 508 | } |
---|
| 509 | return level_stack[k].node_level; |
---|
| 510 | } |
---|
| 511 | |
---|
| 512 | void finalize(Node source) { |
---|
| 513 | std::vector<Node> nodes; |
---|
| 514 | nodes.push_back(source); |
---|
| 515 | while (!nodes.empty()) { |
---|
| 516 | Node node = nodes.back(); |
---|
| 517 | nodes.pop_back(); |
---|
| 518 | for (OutEdgeIt it(*graph, node); it != INVALID; ++it) { |
---|
| 519 | if ((*_level)[graph->target(it)] >= 0 && (*_arborescence_map)[it]) { |
---|
| 520 | (*_level)[graph->target(it)] = -1; |
---|
| 521 | nodes.push_back(graph->target(it)); |
---|
| 522 | } else { |
---|
| 523 | _arborescence_map->set(it, false); |
---|
| 524 | } |
---|
| 525 | } |
---|
| 526 | } |
---|
| 527 | (*_level)[source] = -1; |
---|
| 528 | } |
---|
| 529 | |
---|
| 530 | }; |
---|
| 531 | |
---|
| 532 | /// \ingroup spantree |
---|
| 533 | /// |
---|
| 534 | /// \brief Function type interface for MinCostArborescence algorithm. |
---|
| 535 | /// |
---|
| 536 | /// Function type interface for MinCostArborescence algorithm. |
---|
| 537 | /// \param graph The Graph that the algorithm runs on. |
---|
| 538 | /// \param cost The CostMap of the edges. |
---|
| 539 | /// \param source The source of the arborescence. |
---|
| 540 | /// \retval arborescence The bool EdgeMap which stores the arborescence. |
---|
| 541 | /// \return The cost of the arborescence. |
---|
| 542 | /// |
---|
| 543 | /// \sa MinCostArborescence |
---|
| 544 | template <typename Graph, typename CostMap, typename ArborescenceMap> |
---|
| 545 | typename CostMap::Value minCostArborescence(const Graph& graph, |
---|
| 546 | const CostMap& cost, |
---|
| 547 | typename Graph::Node source, |
---|
| 548 | ArborescenceMap& arborescence) { |
---|
| 549 | typename MinCostArborescence<Graph, CostMap> |
---|
| 550 | ::template DefArborescenceMap<ArborescenceMap> |
---|
| 551 | ::Create mca(graph, cost); |
---|
| 552 | mca.arborescenceMap(arborescence); |
---|
| 553 | mca.run(source); |
---|
| 554 | return mca.arborescenceCost(); |
---|
| 555 | } |
---|
| 556 | |
---|
| 557 | } |
---|
| 558 | |
---|
| 559 | #endif |
---|
| 560 | |
---|
| 561 | // Hilbert - Huang |
---|